Son Doong Cave, Vietnam: Largest Cave in the World

At more than 200m high, 150m wide and 5km long, the Hang Son Doong cave in Vietnam is a solutional cave in Phong Nha-Kẻ Bàng National Park, Bố Trạch District, Quảng Bình Province, Vietnam. It is the biggest known cave in the world; It is so big that it has its own river, jungle and climate.It was formed in Carboniferous / Permian limestone.

Son Doong Cave was found by a local man named Hồ-Khanh in 1991. The whistling sound of wind and roar of a rushing stream in the cave heard through the entrance as well as the steep descent prevented the local people from entering the cave. The cave become internationally known after a group of scientists from the British Cave Research Association, led by Howard and Deb Limbert, conducted a survey in Phong Nha-Kẻ Bàng from 10 to 14 April, 2009.